in coastal regions and in small islands
Hurricane impact on beaches in the eastern Caribbean Islands 1989 - 1995
THE 1995 HURRICANE SEASON
The Caribbean hurricane season extends from June 1st to
November 30th. Many hurricanes
start as weak, low pressure systems known as tropical waves, off the coast of
West Africa. During their journey
westward across the Atlantic Ocean some of these tropical waves develop into
hurricanes. Hurricanes are graded
according to intensity on the Saffir-Simpson scale as follows:
|Category 1||winds||74 - 95 m/h||118-152 km/h|
|Category 2||winds||96 - 110 m/h||154-176 km/h|
|Category 3||winds||111 - 130 m/h||178-208 km/h|
|Category 4||winds||131 - 155 m/h||210-248 km/h|
|Category 5||winds||>155 m/h||>248 km/h|
Several climatic factors interact to determine whether a
particular hurricane season is active or not.
Rainfall in the Sahel region of West Africa.
For the past two decades a drought in the Sahel region of West Africa
suppressed hurricane formation. Now
that the drought has ended, conditions favor the formation of hurricanes.
El Nino - this is a vast current of warm water in the equatorial Pacific
which generates strong low-level westerly winds.
These winds inhibit hurricane formation by cutting through developing
storms. During the years when
El Nino is active, there are fewer hurricanes in the Caribbean region.
Stratospheric winds - these circle the globe at the equator at the
uppermost level of the atmosphere. They
reverse direction every 12-16 months. There
is more intense hurricane activity when these winds blow from the west.
High sea surface temperatures in the Atlantic between West Africa and the
Caribbean Sea increase the likelihood of hurricane growth.
The 1995 hurricane season was the most active year on
record after 1933 (Gray et al.,
1996). There were
nineteen tropical storms, eleven of which became hurricanes.
The months of August and September saw the most intense activity.
The three main storms to affect the eastern Caribbean Islands were:
|Tropical Storm Iris||(26-27th August, 1995)|
|Hurricane Luis||(4-6th September, 1995)|
|Hurricane Marilyn||(15-16th September, 1995).|
Figure 3 shows the tracks of these three storms as they moved through the eastern Caribbean.
|Figure 3. Tracks of the 1995 Storms
Affecting the Eastern
Hurricane Iris developed in the Atlantic Ocean on August 23rd, 1995, and moved towards the Lesser Antilles. About 160 km east of the Windward Islands, the storm was downgraded to a tropical storm. It then proceeded to move up the chain of islands from St. Lucia to Anguilla, see Figure 3. Had this storm continued at full hurricane strength, then there would have been enormous damage to the Caribbean region as each island was impacted. On the 27th August, Tropical Storm Iris moved out into the Atlantic Ocean.
Meanwhile out in the Atlantic Ocean, Hurricane Luis formed on August 28th, 1995, and moved steadily westwards towards the Leeward Islands. This was a huge, category 4 hurricane, the system measured more than 1,120 km across and hurricane force winds extended out 112 km from the centre. The centre of the storm moved over Antigua-Barbuda, St. Maarten and Anguilla before moving out into the Atlantic Ocean. This storm caused extensive damage to the islands north of Dominica, see Figure 3.
The third storm to affect the region was Hurricane Marilyn. This formed out in the Atlantic Ocean, east of Barbados, on September 12th, 1995. It passed just north of Barbados, east of the Windward Islands and passed directly over St. Thomas as a very intense category 3 hurricane.
Besides the environmental damage, these storms caused extensive damage to infrastructure and housing in the affected islands. In Antigua and Barbuda after Hurricane Luis most of the hotels were forced to close for the remainder of the year for extensive rehabilitation. As a result, stop-over visitor arrivals fell by 15% from 1994 levels (Caribbean Development Bank, 1996), this negatively impacted employment and income. In Dominica there was substantial damage to roads and sea defences and in particular to the agricultural sector, where the banana crop was virtually eliminated and there was widespread destruction of foodcrops.